First thing you need to execute the script in the target cube, suppose u want to fetch the value of A from plan 1 into B which is in Plan B then you should execute it in Plan B..
In your script, you are missing the location alias which is reference of the source cube.
The script should be:
FIX (including dimensions of Plan1)

If you have a location alias and if you are referring the same variable. then no need to create it..
If your script is not working, then it might be the issue of block creation in the target
cube where you are running this script.
Create block for that combination and then run the script...and if it works,
then you have to write the block creation logic...